An argument with which you may be familiar concerns the objectivity of morality. Many persons of religious faith believe that any moral claim or action ultimately must issue from a transcendent source, which they define as a supernatural agent or force. Without a supernatural entity or force, which exists as a universal and timeless thing, morality is merely the product of the subjective mind and, as such, its advocates can claim no final objective authority over the behavior of the individual. Thus secularists, while they may articulate moral sentiments and advocate rules appealing to their attendant values, have no real foundation upon which to build an ethical and legal structure. Societal arrangements change over time and space (they are culturally and historically relative), whereas the supernatural agent or force, which we shall call “God,” is intransitive. In short, no religion, no morality. It follows, therefore, that, without “God,” there is no reason to be or do good.
I know of no claim that suffers from greater invalidity and unsoundness. When one examines culture and history, he finds, among the many things that a particular people produce, concrete religious systems. The first thing that strikes the observer, after examining a handful of different cultures, is the great degree of cross-cultural variability in religious systems and associated aspects of the moral order these religious systems are alleged to underpin. With different religions come different moral systems, which mean there are different ideas and motives for a person to be or do good (or evil). Thus, the evidence demonstrates that appealing to supernatural agents or forces does nothing to make universal or immemorial any particular moral order. On the contrary, on the surface, morality is found to be as culturally and historically relative as religion.
The only way out of this relativity problem, from a religious perspective, is to assert (and assert one must, since one cannot prove) that one religion is the only true religion, while all of the others are false religions. But such an assertion is self-evidently subjective, and thus cannot be the objective grounds for arguing that religious morality is superior to secular morality. Belief in the supernatural is, after all, a matter of faith. Indeed, what we find when we look at several specific religions—each of which claims to be the one true religion—are practices accepted and even encouraged by religious leaders and texts that are recognized as moral wrongs in the present day.
The Judeo-Christian Bible, for example, advocates the killing of defiant children, homosexuals, and infidels, acts that widely recognized as criminal acts. The Bible also justifies slavery. Yet virtually every Christian and Jew opposes slavery. How is it possible that people recognize the immorality of prescriptions in the Bible if the Bible is the sole source of morality for adherents to this religion? Does the obvious truth that religion provides no objective foundation for morality mean that morality is doomed to relativism and subjectivism?
For a very straightforward reason, I believe the answer to this question is no. Here, social science (a secular system of thought) provides us with the needed tools to identify objective features of morality. A moral order is an emergent property of human society irrespective of any religious sentiment. Each Homo sapiens, as an accident of biological evolution, must live in society to become human in the moral sense. Morality is, at its core, the rules that organize individual action or behavior sufficient for the existence of human being and that make the continuation of society possible. Thus a universal morality is to be found in the universal features of human interaction and relations.
Sometimes a particular religion will reflect these transhistorical features of human society, such as is seen in the so-called “golden rule,” a prescription found, if only ideally, everywhere. Oftentimes, however, religious sentiments disrupts the basic decent human impulses given to us by deeper societal relations. Here we find those religious texts advocating killing and oppressing human beings in the name of a god or gods. What we find when we study the matter from a position external to the religious system is that the leaders and scriptures are justifying power relations peculiar to a concrete social order; in other words, they wrap exploitation and oppression in the language of morality. The religiously-devoted in these instances are not oppressing others for the sake of morality, but for the sake of maintaining power and wealth, that is, perpetuating an unjust, or immoral, if you will, state of affairs. In this way, religion can be, although this is not always true, the epitome of immorality.